Field of the Invention
The present disclosure relates to the displaying of an image on a motor vehicle windshield.
Description of the Related Art
Systems where an image is projected, in direct projection, on a transparent diffusing film pasted on the windshield inside of the vehicle have already been provided. Such systems enable to provide an occupier of the vehicle with information overlaid to the outer scene visible through the windshield.
Existing systems however have various disadvantages. In particular, a disadvantage is that part of the light projected on the diffusing film is transmitted by this film, crosses the windshield, and is projected outside of the vehicle. This raises issues in certain applications. This particularly makes existing systems incompatible with certain vehicles, for example, military vehicles where, for confidentiality reasons, it is not acceptable for the information projected for the vehicle occupiers to be readable from the outside of the vehicle. This further makes existing systems incompatible with certain stealth vehicles where the light transmitted through the diffusing film and the windshield could make the vehicle easily detectable.
Another disadvantage of existing systems is their bulk. Indeed, the projector, located inside of the vehicle, should be placed opposite the diffusing film, at a relatively long distance from the windshield to enable to display an image of satisfactory size. This imposes positioning constraints, particularly to guarantee that no object or occupier of the vehicle intercepts the light beam during the system use. Since motor vehicle passenger compartments generally are relatively small and cluttered spaces, such positioning constraints are sometimes difficult to comply with.
It would be desirable to have a windshield image display system at least partly overcoming some of the disadvantages of existing systems.